Thanks for the questions and suggestions, please send more. Don't think that "my question is to dumb/obvious/embarrassing to ask". Everyone (me included) was a noob once. Also, I've had a few people ask if I'm employed by, a consultant for, or otherwise affiliated with Superfly/AC Entertainment (the folks who put on Bonnaroo). I'm not.
Security at Bonnaroo
This is not going to be a thesis on how to get drugs or other illicit substances into Bonnaroo, sorry. What I do want to do is to give an overview of what to expect.
There will probably be a line of cars on the interstate and depending on when you arrive you might wait in line for 4+ hours. Be aware that there will be a lot of State Police around. They are mostly concerned with keeping the line moving and making sure people are safe but they are not blind. In Tennessee the driver is not permitted to have an open container of alcohol, here is an overview of the law. When you are waiting in line on the interstate you are still legally driving on a public road so the normal rules apply.
When you pull into Bonnaroo there will be a row of security "toll booths". The blog's title picture is the line for the toll booths. Your vehicle will be searched by Bonnaroo security. Most of the people working security are not "professionals" but younger people working 'roo to get a free ticket. For the most part they are looking for glass bottles, kegs, nitrous oxide tanks and large quantities of other drugs. Weapons are a no-no as well. A small pocket knife shouldn't be a problem, a hatchet might be. The security has always been polite to me, they'll look into your coolers, glove compartment, car consoles, under seats, etc. Unless they find something or you act "suspicious" or like an ass they probably won't tear your car apart. At least one year the State Police were randomly searching every 20th or 40th car, I'd imagine their searches would be more thorough. It should go without saying, but everyone in the vehicle needs to have a ticket. Don't wait until you get to Manchester to realize you left your tix on your desk. Be safe, put you tix in the glove compartment the night before (and still check in the morning).
In the campsites security is mostly focused on keeping the peace and keeping people safe. The most visible security is the horse mounted patrols. The same security outfit has been working 'roo for as long as I can remember, they really are quite professional. In my experience they have never been anything other than respectful and helpful, they understand that keeping the peace is more important mindlessly harassing people. They have walkie-talkies, so if you need help for whatever reason, flag one down and they can put a call in for you.
There is a security checkpoint to get into Centeroo (the main area where the stages are). This is the most extensive check you'll go through. They'll look though any bags you have and pat you down. They will take or turn you away for: open liquid containers that have something in them (empty bottles or sealed water bottles should be ok), beer or liquor, drugs, big folding chairs, weapons, bootleg teeshirts etc. The rules say no "professional" type cameras, I've not seen anyone have a problem with that. I still wouldn't recommend bringing this though.